Lately I have been focusing a lot of my attention on building the living roof (a.k.a. green roof, sod roof, or turf roof). Last week, I finished building an edge board – a sort of retaining wall around the perimeter of the roof to help hold the soil from sliding off the roof. I debated quite a bit about how to construct the edge board, and eventually I decided that I would use round black locust logs spiked into the rafter ends with giant 8″ nails. Unfortunately, the logs only extend a couple of inches above the height of the roof, so it’s less of a retaining “wall” and more of a little edge “bump.” (See above photo for a better idea.) I’m not too afraid of soil sliding off the roof, so I’m not that worried.

Cutting sod squares

Originally, my plan was to use loose soil on most of the roof. I thought I’d use loose soil because we are having some road work done in the near future, and much of the topsoil will be scraped and made available. Instead, I am using sod squares. Ma’ikwe, another Dancing Rabbit member is building a new home this year, and she very kindly gave me permission to cut sod from the footprint of her future home. Sod is much more ideal than loose soil because it already has grasses and root structure established.

I’ve gotten into a pretty good groove cutting the sod using a simple flat trench shovel. Each square is something like 4-6″ thick and very heavy. I’ve moved dozens of wheelbarrows full of this sod to my building site.

Loading the sod

Recently, I put a few of these sod pieces (or “turves”) up on the edge of the roof. I decided to fold the EPDM under itself at the roof edge and slightly up over the log edge board. It looks a little less than ideal, but then again, the soil will eventually settle and perhaps cover the EPDM from sight. I’m not sure. It’s kind of an experiment. I want the EPDM to protect the logs, but I don’t want it to come all the way around the edge. I’m also want to have the option of adding a gutter to the edge in the future.

Next week, I’m planning to have a work party to completely cover the roof in soil. This is a huge step!